If you trade options, consider optionshouse. I've been trading with them for about 2 years, and trade around 10,000 contracts per year.

$9.95 for options, flat rate, no per-contract fee. Given my order sizes, that's a huge savings!
$14.95 for option spreads, also flat rate.
$2.95 for stock.

Live updating option chains! Great core platform!

I've never waited more than 1 minute on the phone for customer service or the trade desk.

Never had trouble with deposit/withdrawal. ACH deposits require 3 day hold; ACH withdrawals are same day/next day.

Cons: data services (historical, etc.) are there, but hard to find -- I prefer optionsxpress for that; they also don't display the options ticker itself on the chain.